Chrome Markdown Viewer: Read .md Files in Your Browser

A Chrome Markdown viewer is an extension that renders .md files as formatted pages instead of raw text when you open them in the browser. The main choices are Markdown Viewer by simov, Markdown Reader, Markdown Preview Plus, and MarkView. This guide compares them, fixes the "not working" problem step by step, and covers the no-extension route for phones and locked-down machines.

What Does a Markdown Viewer Chrome Extension Do?

Chrome doesn't know what Markdown is. Open a local README.md with file:/// and you get a wall of plain text with the hash marks and asterisks showing. Depending on how a server labels the file, Chrome may offer to download it instead.

A viewer extension (some listings call it a markdown plugin) watches for URLs that end in .md or respond with a text/markdown content type. It runs the text through a Markdown parser and replaces the page with rendered HTML, usually styled to look like GitHub.

That's useful in three situations: reading documentation that lives on disk, previewing a file from a local dev server, and reading raw Markdown on sites that don't render it. It's also the only way to get a live-reloading preview in the browser without a build tool.

What a markdown viewer for Chrome doesn't do is edit. For that you want an editor with a preview pane, on the desktop or in the browser. The VS Code Markdown guide and the section at the end of this post cover both.

Which Chrome Markdown Extension Should You Install?

Four extensions account for most installs. The numbers are what the Chrome Web Store showed on 11 September 2026; they'll drift.

We prefer Markdown Viewer by simov. It's open source under the MIT license. It uses Manifest V3 (its manifest.chrome.json declares manifest_version: 3), so it survived Chrome's 2024 to 2025 removal of Manifest V2 extensions. And its options cover almost everything. You get a choice between the marked and remark parsers, GFM on by default, Mermaid and MathJax toggles, a table of contents, and autoreload for file:// and localhost URLs. The GitHub repository documents every setting.

The honest limitation is its release cadence. Version 5.3 dates from May 2024, and while the repository's Firefox branch had commits in late 2025, a store update hasn't followed. If you'd rather have something updated this month, Markdown Reader's 3.6.30 shipped on the day we checked. Markdown Preview Plus is the one older forum threads recommend for auto-converting files on open, and it still works, but its version number and pace suggest maintenance mode.

How Do You Set Up a Chrome Markdown Viewer for Local Files?

Installing is one click on the Web Store page. Reading local files takes one more step that every extension needs and every "not working" report skips:

1. Open chrome://extensions in the address bar.
2. Find the extension and click Details.
3. Turn on the switch labelled Allow access to file URLs.

Chrome's extension docs state that the file:/// match pattern "requires the user to manually grant access", which is why the switch is off for every extension until you flip it. Once it's on, type file:///Users/you/project/README.md (or drag the file into a tab) and the rendered page appears. For remote files, simov's extension additionally asks you to add each origin under Advanced Options, or to allow all origins, before it will render pages from that site.

Markdown Viewer also detects the text/markdown content type and lets you match paths with a regular expression. A dev server that serves .md files under a different extension can therefore still be rendered. The GitHub Markdown cheat sheet is worth keeping open, because GFM is what these extensions render and its tables, task lists, and alerts are what people usually check first.

Why Isn't the Markdown Viewer Working in Chrome?

Work down this list; the first two fix most cases.

1. File URL access is off. The switch above. Symptom: file:/// pages show raw text or download.
2. The file doesn't end in .md. The extensions match on extension or content type. notes.markdown, README with no extension, and .txt files aren't matched unless you add a path rule.
3. Chrome downloaded the file. If the server sends a Content-Disposition: attachment header, Chrome saves the file instead of handing it to the extension. Open the raw URL, or the file locally.
4. The origin isn't allowed. For remote pages, simov's extension needs the site added under Advanced Options. Other extensions may request access to all sites at install time instead.
5. The extension is Manifest V2. Chrome disabled remaining Manifest V2 extensions in the stable channel during 2024 and 2025, with enterprise exemptions ending in June 2025. If an old viewer shows as disabled on chrome://extensions with a "no longer supported" note, replace it with one of the four above.
6. Policy blocks it. On a managed work or school machine, chrome://policy may list ExtensionInstallBlocklist. The extension won't install and there's no workaround except the no-extension route below.
7. Incognito. Extensions are off in Incognito unless you enable Allow in Incognito on the Details page.

Does the Chrome Markdown Viewer Work on Android or Edge?

Not on Android phones. Google's help page for installing extensions has a phone section, but the button there is Add to Desktop. It queues the install for your next desktop session rather than running the extension on the phone. The Markdown Viewer app in the Play Store that ranks for this search is an unrelated native app, not the extension. On a phone, use the no-extension route below.

Edge is the opposite story. It's Chromium-based and installs Chrome Web Store extensions directly. Microsoft's Edge support page walks through it: open the Web Store in Edge, click Get, and select Allow when prompted to allow extensions from other stores. simov's extension and MarkView also offer Edge installs directly. Brave, Opera, and Vivaldi install from the Chrome Web Store the same way.

Read Markdown in Chrome Without Any Extension

When extensions are blocked, you're on a phone, or you just want to read one file, skip the install. Open the editor in any browser and drop the .md file into it or paste the contents. The right pane renders it with GFM tables, task lists, syntax highlighting, and Mermaid diagrams. It's what we use on machines we don't control, and it's the same renderer whether you're on Chrome, Safari, or a phone. Try it here:

flowchart LR
A[.md file] --- B[Extension or this editor] --- C[Rendered page]

Mermaid support is the one thing worth checking before you pick an extension, because the "Chrome Markdown viewer Mermaid" search is common and only some extensions render diagrams. Markdown Viewer by simov has a Mermaid toggle; the Mermaid diagrams guide shows the syntax, and the editor above renders the fence live. For a rendered view on the desktop without a browser at all, the Markdown viewer for Mac guide covers Quick Look plugins and native apps.

Chrome Markdown Viewer FAQ

Pick a Chrome Markdown viewer by what you need rendered: simov's Markdown Viewer for open source and the widest option set, Markdown Reader for frequent updates, and either one only after you've flipped Allow access to file URLs. On a phone, a managed laptop, or for a single file, the editor renders the same Markdown with nothing to install.